diff --git a/3rdparty/SoundTouch/CMakeLists.txt b/3rdparty/SoundTouch/CMakeLists.txt
index fa2cc7b15c..2c8fc54451 100644
--- a/3rdparty/SoundTouch/CMakeLists.txt
+++ b/3rdparty/SoundTouch/CMakeLists.txt
@@ -9,22 +9,27 @@ set(CommonFlags
     -march=prescott
     )
 
+set(OptimizationFlags
+    -Os
+    -W
+    )
+
 # Debug - Build
 if(CMAKE_BUILD_TYPE STREQUAL Debug)
 	# add defines
-	add_definitions(${CommonFlags} -g -O0)
+	add_definitions(${CommonFlags} -g)
 endif(CMAKE_BUILD_TYPE STREQUAL Debug)
 
 # Devel - Build
 if(CMAKE_BUILD_TYPE STREQUAL Devel)
 	# add defines
-	add_definitions(${CommonFlags} -O1 -g -W)
+	add_definitions(${CommonFlags} ${OptimizationFlags})
 endif(CMAKE_BUILD_TYPE STREQUAL Devel)
 
 # Release - Build
 if(CMAKE_BUILD_TYPE STREQUAL Release)
 	# add defines
-	add_definitions(${CommonFlags} -fexpensive-optimizations -O3 -Os -W)
+	add_definitions(${CommonFlags} ${OptimizationFlags})
 endif(CMAKE_BUILD_TYPE STREQUAL Release)
 
 # variable with all sources of this library
diff --git a/3rdparty/bzip2/CMakeLists.txt b/3rdparty/bzip2/CMakeLists.txt
index 81ce43e821..b4423f31dc 100644
--- a/3rdparty/bzip2/CMakeLists.txt
+++ b/3rdparty/bzip2/CMakeLists.txt
@@ -9,22 +9,27 @@ set(CommonFlags
     -march=prescott
     )
 
+set(OptimizationFlags
+    -Os
+    -W
+    )
+
 # Debug - Build
 if(CMAKE_BUILD_TYPE STREQUAL Debug)
 	# add defines
-	add_definitions(${CommonFlags} -g -O0)
+	add_definitions(${CommonFlags} -g)
 endif(CMAKE_BUILD_TYPE STREQUAL Debug)
 
 # Devel - Build
 if(CMAKE_BUILD_TYPE STREQUAL Devel)
 	# add defines
-	add_definitions(${CommonFlags} -O1 -g -W)
+	add_definitions(${CommonFlags} ${OptimizationFlags} -g)
 endif(CMAKE_BUILD_TYPE STREQUAL Devel)
 
 # Release - Build
 if(CMAKE_BUILD_TYPE STREQUAL Release)
 	# add defines
-	add_definitions(${CommonFlags} -fexpensive-optimizations -O3 -Os -W)
+	add_definitions(${CommonFlags} ${OptimizationFlags})
 endif(CMAKE_BUILD_TYPE STREQUAL Release)
 
 # variable with all sources of this library
diff --git a/3rdparty/liba52/CMakeLists.txt b/3rdparty/liba52/CMakeLists.txt
index 1763a07baf..d2a323907a 100644
--- a/3rdparty/liba52/CMakeLists.txt
+++ b/3rdparty/liba52/CMakeLists.txt
@@ -10,7 +10,6 @@ set(CommonFlags
     )
 
 set(OptimizationFlags
-    -O2
     -Os
     )
 
diff --git a/3rdparty/zlib/CMakeLists.txt b/3rdparty/zlib/CMakeLists.txt
index 3a7fdf6cd5..534a7b073f 100644
--- a/3rdparty/zlib/CMakeLists.txt
+++ b/3rdparty/zlib/CMakeLists.txt
@@ -8,22 +8,26 @@ set(CommonFlags
     -m32
     )
 
+set(OptimizationFlags
+    -Os
+    )
+
 # Debug - Build
 if(CMAKE_BUILD_TYPE STREQUAL Debug)
 	# add defines
-	add_definitions(${CommonFlags} -g -O0)
+	add_definitions(${CommonFlags} -g)
 endif(CMAKE_BUILD_TYPE STREQUAL Debug)
 
 # Devel - Build
 if(CMAKE_BUILD_TYPE STREQUAL Devel)
 	# add defines
-	add_definitions(${CommonFlags} -O2)
+	add_definitions(${CommonFlags} ${OptimizationFlags})
 endif(CMAKE_BUILD_TYPE STREQUAL Devel)
 
 # Release - Build
 if(CMAKE_BUILD_TYPE STREQUAL Release)
 	# add defines
-	add_definitions(${CommonFlags} -fexpensive-optimizations -O3)
+	add_definitions(${CommonFlags} ${OptimizationFlags})
 endif(CMAKE_BUILD_TYPE STREQUAL Release)
 
 # variable with all sources of this library