diff --git a/indra/cmake/00-Common.cmake b/indra/cmake/00-Common.cmake
index fa0871ddc..ebe3e881d 100644
--- a/indra/cmake/00-Common.cmake
+++ b/indra/cmake/00-Common.cmake
@@ -113,7 +113,7 @@ if (WINDOWS)
     
 endif (WINDOWS)
 
-set (GCC_EXTRA_OPTIMIZATIONS "-ffast-math -frounding-math")
+set (GCC_EXTRA_OPTIMIZATIONS "-ffast-math")
 
 if (LINUX)
   set(CMAKE_SKIP_RPATH TRUE)
@@ -182,6 +182,8 @@ if (LINUX)
       -pthread
       )
 
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")
+
   add_definitions(-DAPPID=secondlife)
   add_definitions(-fvisibility=hidden)
   # don't catch SIGCHLD in our base application class for the viewer - some of our 3rd party libs may need their *own* SIGCHLD handler to work.  Sigh!  The viewer doesn't need to catch SIGCHLD anyway.
@@ -200,10 +202,10 @@ if (LINUX)
     if (NOT STANDALONE)
   	set(MARCH_FLAG " -march=pentium4")
     endif (NOT STANDALONE)
-    set(CMAKE_CXX_FLAGS_RELEASESSE2 "${CMAKE_CXX_FLAGS_RELEASESSE2}${MARCH_FLAG} -mfpmath=sse -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
-    set(CMAKE_C_FLAGS_RELEASESSE2 "${CMAKE_C_FLAGS_RELEASESSE2}${MARCH_FLAG} -mfpmath=sse -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
-    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}${MARCH_FLAG} -mfpmath=sse -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
-    set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO}${MARCH_FLAG} -mfpmath=sse -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
+    set(CMAKE_CXX_FLAGS_RELEASESSE2 "${CMAKE_CXX_FLAGS_RELEASESSE2}${MARCH_FLAG} -mfpmath=sse,387 -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
+    set(CMAKE_C_FLAGS_RELEASESSE2 "${CMAKE_C_FLAGS_RELEASESSE2}${MARCH_FLAG} -mfpmath=sse,387 -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
+    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}${MARCH_FLAG} -mfpmath=sse,387 -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
+    set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO}${MARCH_FLAG} -mfpmath=sse,387 -msse2 ${GCC_EXTRA_OPTIMIZATIONS}")
   endif (${ARCH} STREQUAL "x86_64")
 
   set(CMAKE_CXX_FLAGS_DEBUG "-fno-inline ${CMAKE_CXX_FLAGS_DEBUG} -msse2")