diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 3409c49d3..3514fb477 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -549,6 +549,7 @@ if(${SRB2_CONFIG_USEASM})
 	endif()
 	set(SRB2_USEASM ON)
 	add_definitions(-DUSEASM)
+	set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} -msse3 -mfpmath=sse)
 else()
 	set(SRB2_USEASM OFF)
 	add_definitions(-DNONX86 -DNORUSEASM)
diff --git a/src/Makefile b/src/Makefile
index 2fe0b26cd..5d5db056f 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -277,7 +277,7 @@ OPTS += -DCOMPVERSION
 
 ifndef NONX86
 ifndef GCC29
-	ARCHOPTS?=-march=pentium
+	ARCHOPTS?=-msse3 -mfpmath=sse
 else
 	ARCHOPTS?=-mpentium
 endif