diff --git a/src/main/java/lwjake2/client/CL_parse.java b/src/main/java/lwjake2/client/CL_parse.java
index 93927b3..e480cb2 100644
--- a/src/main/java/lwjake2/client/CL_parse.java
+++ b/src/main/java/lwjake2/client/CL_parse.java
@@ -76,7 +76,7 @@ public class CL_parse {
         RandomAccessFile fp;
         String name;
 
-        if (filename.indexOf("..") != -1) {
+        if (filename.contains("..")) {
             log.warn("Refusing to download a path with ..");
             return true;
         }
@@ -147,7 +147,7 @@ public class CL_parse {
 
         filename = Cmd.Argv(1);
 
-        if (filename.indexOf("..") != -1) {
+        if (filename.contains("..")) {
             log.warn("Refusing to download a path with ..");
             return;
         }
diff --git a/src/main/java/lwjake2/client/Menu.java b/src/main/java/lwjake2/client/Menu.java
index 4b69a77..fae39d9 100644
--- a/src/main/java/lwjake2/client/Menu.java
+++ b/src/main/java/lwjake2/client/Menu.java
@@ -4248,7 +4248,7 @@ public final class Menu extends Key {
                     + s.parent.y, s.name);
         }
 
-        if (s.itemnames[s.curvalue].indexOf('\n') == -1) {
+        if (!s.itemnames[s.curvalue].contains("\n")) {
             Menu_DrawString(RCOLUMN_OFFSET + s.x + s.parent.x,
                     s.y + s.parent.y, s.itemnames[s.curvalue]);
         } else {
diff --git a/src/main/java/lwjake2/game/GameTarget.java b/src/main/java/lwjake2/game/GameTarget.java
index 23041ff..2902c86 100644
--- a/src/main/java/lwjake2/game/GameTarget.java
+++ b/src/main/java/lwjake2/game/GameTarget.java
@@ -38,7 +38,7 @@ public class GameTarget {
                     + Lib.vtos(ent.s.origin) + "\n");
             return;
         }
-        if (GameBase.st.noise.indexOf(".wav") < 0)
+        if (!GameBase.st.noise.contains(".wav"))
             buffer = "" + GameBase.st.noise + ".wav";
         else
             buffer = GameBase.st.noise;
@@ -438,7 +438,7 @@ public class GameTarget {
             }
 
             // if going to a new unit, clear cross triggers
-            if (self.map.indexOf('*') > -1)
+            if (self.map.contains("*"))
                 GameBase.game.serverflags &= ~(Defines.SFL_CROSS_TRIGGER_MASK);
 
             PlayerHud.BeginIntermission(self);
diff --git a/src/main/java/lwjake2/game/Info.java b/src/main/java/lwjake2/game/Info.java
index 0118aae..5bd8db3 100644
--- a/src/main/java/lwjake2/game/Info.java
+++ b/src/main/java/lwjake2/game/Info.java
@@ -57,17 +57,17 @@ public class Info {
         if (value == null || value.length() == 0)
             return s;
 
-        if (key.indexOf('\\') != -1 || value.indexOf('\\') != -1) {
+        if (key.contains("\\") || value.contains("\\")) {
             log.warn("Can't use keys or values with a \\");
             return s;
         }
 
-        if (key.indexOf(';') != -1) {
+        if (key.contains(";")) {
             log.warn("Can't use keys or values with a semicolon");
             return s;
         }
 
-        if (key.indexOf('"') != -1 || value.indexOf('"') != -1) {
+        if (key.contains("\"") || value.contains("\"")) {
             log.warn("Can't use keys or values with a \"");
             return s;
         }
@@ -98,7 +98,7 @@ public class Info {
 
         StringBuffer sb = new StringBuffer(512);
 
-        if (key.indexOf('\\') != -1) {
+        if (key.contains("\\")) {
             log.warn("Can't use a key with a \\");
             return s;
         }
diff --git a/src/main/java/lwjake2/game/PlayerHud.java b/src/main/java/lwjake2/game/PlayerHud.java
index f1c5fea..b8e3e07 100644
--- a/src/main/java/lwjake2/game/PlayerHud.java
+++ b/src/main/java/lwjake2/game/PlayerHud.java
@@ -94,7 +94,7 @@ public class PlayerHud {
         GameBase.level.intermissiontime = GameBase.level.time;
         GameBase.level.changemap = targ.map;
 
-        if (GameBase.level.changemap.indexOf('*') > -1) {
+        if (GameBase.level.changemap.contains("*")) {
             if (GameBase.coop.value != 0) {
                 for (i = 0; i < GameBase.maxclients.value; i++) {
                     client = GameBase.g_edicts[1 + i];
diff --git a/src/main/java/lwjake2/qcommon/Cvar.java b/src/main/java/lwjake2/qcommon/Cvar.java
index 6825cce..de39ff7 100644
--- a/src/main/java/lwjake2/qcommon/Cvar.java
+++ b/src/main/java/lwjake2/qcommon/Cvar.java
@@ -442,11 +442,11 @@ public class Cvar {
      * Some characters are invalid for info strings.
      */
     static boolean InfoValidate(String s) {
-        if (s.indexOf("\\") != -1)
+        if (s.contains("\\"))
             return false;
-        if (s.indexOf("\"") != -1)
+        else if (s.contains("\""))
             return false;
-        if (s.indexOf(";") != -1)
+        else if (s.contains(";"))
             return false;
         return true;
     }
diff --git a/src/main/java/lwjake2/render/lwjgl/Main.java b/src/main/java/lwjake2/render/lwjgl/Main.java
index 57ecab7..8f80797 100644
--- a/src/main/java/lwjake2/render/lwjgl/Main.java
+++ b/src/main/java/lwjake2/render/lwjgl/Main.java
@@ -1095,25 +1095,25 @@ public abstract class Main extends Base {
         String renderer_buffer = gl_config.renderer_string.toLowerCase();
         String vendor_buffer = gl_config.vendor_string.toLowerCase();
 
-        if (renderer_buffer.indexOf("voodoo") >= 0) {
-            if (renderer_buffer.indexOf("rush") < 0)
+        if (renderer_buffer.contains("voodoo")) {
+            if (!renderer_buffer.contains("rush"))
                 gl_config.renderer = GL_RENDERER_VOODOO;
             else
                 gl_config.renderer = GL_RENDERER_VOODOO_RUSH;
         }
-        else if (vendor_buffer.indexOf("sgi") >= 0)
+        else if (vendor_buffer.contains("sgi"))
             gl_config.renderer = GL_RENDERER_SGI;
-        else if (renderer_buffer.indexOf("permedia") >= 0)
+        else if (renderer_buffer.contains("permedia"))
             gl_config.renderer = GL_RENDERER_PERMEDIA2;
-        else if (renderer_buffer.indexOf("glint") >= 0)
+        else if (renderer_buffer.contains("glint"))
             gl_config.renderer = GL_RENDERER_GLINT_MX;
-        else if (renderer_buffer.indexOf("glzicd") >= 0)
+        else if (renderer_buffer.contains("glzicd"))
             gl_config.renderer = GL_RENDERER_REALIZM;
-        else if (renderer_buffer.indexOf("gdi") >= 0)
+        else if (renderer_buffer.contains("gdi"))
             gl_config.renderer = GL_RENDERER_MCD;
-        else if (renderer_buffer.indexOf("pcx2") >= 0)
+        else if (renderer_buffer.contains("pcx2"))
             gl_config.renderer = GL_RENDERER_PCX2;
-        else if (renderer_buffer.indexOf("verite") >= 0)
+        else if (renderer_buffer.contains("verite"))
             gl_config.renderer = GL_RENDERER_RENDITION;
         else
             gl_config.renderer = GL_RENDERER_OTHER;
@@ -1164,8 +1164,8 @@ public abstract class Main extends Base {
         /*
         ** grab extensions
         */
-        if (gl_config.extensions_string.indexOf("GL_EXT_compiled_vertex_array") >= 0
-            || gl_config.extensions_string.indexOf("GL_SGI_compiled_vertex_array") >= 0) {
+        if (gl_config.extensions_string.contains("GL_EXT_compiled_vertex_array")
+            || gl_config.extensions_string.contains("GL_SGI_compiled_vertex_array")) {
             log.info("...enabling GL_EXT_compiled_vertex_array");
             //         qglLockArraysEXT = ( void * ) qwglGetProcAddress( "glLockArraysEXT" );
             if (gl_ext_compiled_vertex_array.value != 0.0f)
@@ -1180,7 +1180,7 @@ public abstract class Main extends Base {
             qglLockArraysEXT = false;
         }
 
-        if (gl_config.extensions_string.indexOf("WGL_EXT_swap_control") >= 0) {
+        if (gl_config.extensions_string.contains("WGL_EXT_swap_control")) {
             qwglSwapIntervalEXT = true;
             log.info("...enabling WGL_EXT_swap_control");
         } else {
@@ -1188,7 +1188,7 @@ public abstract class Main extends Base {
             log.info("...WGL_EXT_swap_control not found");
         }
 
-        if (gl_config.extensions_string.indexOf("GL_EXT_point_parameters") >= 0) {
+        if (gl_config.extensions_string.contains("GL_EXT_point_parameters")) {
             if (gl_ext_pointparameters.value != 0.0f) {
                 //             qglPointParameterfEXT = ( void (APIENTRY *)( GLenum, GLfloat ) ) qwglGetProcAddress( "glPointParameterfEXT" );
                 qglPointParameterfEXT = true;
@@ -1239,7 +1239,7 @@ public abstract class Main extends Base {
             log.info("...GL_EXT_shared_texture_palette not found");
         }
 
-        if (gl_config.extensions_string.indexOf("GL_ARB_multitexture") >= 0) {
+        if (gl_config.extensions_string.contains("GL_ARB_multitexture")) {
             log.info("...using GL_ARB_multitexture");
             qglActiveTextureARB = true;
             GL_TEXTURE0 = ARBMultitexture.GL_TEXTURE0_ARB;
diff --git a/src/main/java/lwjake2/server/SV_CCMDS.java b/src/main/java/lwjake2/server/SV_CCMDS.java
index bf87896..7259c79 100644
--- a/src/main/java/lwjake2/server/SV_CCMDS.java
+++ b/src/main/java/lwjake2/server/SV_CCMDS.java
@@ -594,7 +594,7 @@ public class SV_CCMDS {
 
         // if not a pcx, demo, or cinematic, check to make sure the level exists
         map = Cmd.Argv(1);
-        if (map.indexOf(".") < 0) {
+        if (!map.contains(".")) {
             expanded = "maps/" + map + ".bsp";
             if (UnpackLoader.loadFile(expanded) == null) {
 
@@ -636,7 +636,7 @@ public class SV_CCMDS {
         log.warn("Loading game...");
 
         dir = Cmd.Argv(1);
-        if ( (dir.indexOf("..") > -1) || (dir.indexOf("/") > -1) || (dir.indexOf("\\") > -1)) {
+        if ( (dir.contains("..")) || (dir.contains("/")) || (dir.contains("\\"))) {
             log.warn("Bad savedir.");
         }
 
@@ -699,7 +699,7 @@ public class SV_CCMDS {
         }
 
         dir = Cmd.Argv(1);
-        if ( (dir.indexOf("..") > -1) || (dir.indexOf("/") > -1) || (dir.indexOf("\\") > -1)) {
+        if ( (dir.contains("..")) || (dir.contains("/")) || (dir.contains("\\"))) {
             log.warn("Bad savedir.");
         }
         
diff --git a/src/main/java/lwjake2/server/SV_USER.java b/src/main/java/lwjake2/server/SV_USER.java
index 31e8ebf..c48709e 100644
--- a/src/main/java/lwjake2/server/SV_USER.java
+++ b/src/main/java/lwjake2/server/SV_USER.java
@@ -345,7 +345,7 @@ public class SV_USER {
         // hacked by zoid to allow more conrol over download
         // first off, no .. or global allow check
 
-        if (name.indexOf("..") != -1
+        if (name.contains("..")
                 || SV_MAIN.allow_download.value == 0 // leading dot is no good
                 || name.charAt(0) == '.' // leading slash bad as well, must be
                                          // in subdir
diff --git a/src/main/java/lwjake2/sound/lwjgl/LWJGLSoundImpl.java b/src/main/java/lwjake2/sound/lwjgl/LWJGLSoundImpl.java
index 99eb817..83fb4ee 100644
--- a/src/main/java/lwjake2/sound/lwjgl/LWJGLSoundImpl.java
+++ b/src/main/java/lwjake2/sound/lwjgl/LWJGLSoundImpl.java
@@ -542,7 +542,7 @@ public final class LWJGLSoundImpl implements Sound {
         i = 1;
         while (i < Cmd.Argc()) {
             name = Cmd.Argv(i);
-            if (name.indexOf('.') == -1)
+            if (!name.contains("."))
                 name += ".wav";
 
             sfx = RegisterSound(name);