diff --git a/OpenEXR/IlmImf/ImfDwaCompressor.cpp b/OpenEXR/IlmImf/ImfDwaCompressor.cpp
index cd7b5671d3..4985be6287 100644
--- a/OpenEXR/IlmImf/ImfDwaCompressor.cpp
+++ b/OpenEXR/IlmImf/ImfDwaCompressor.cpp
@@ -948,7 +948,7 @@ DwaCompressor::LossyDctDecoderBase::execute ()
                 }
                 else
                 {
-                    #if IMF_HAVE_SSE2
+                    #ifdef IMF_HAVE_SSE2
 
                         __m128i *dst = (__m128i*)&rowBlock[comp][blockx*64];
 
diff --git a/OpenEXR/IlmImf/ImfOptimizedPixelReading.h b/OpenEXR/IlmImf/ImfOptimizedPixelReading.h
index 1c83497ae6..334336a33a 100644
--- a/OpenEXR/IlmImf/ImfOptimizedPixelReading.h
+++ b/OpenEXR/IlmImf/ImfOptimizedPixelReading.h
@@ -60,7 +60,7 @@ class OptimizationMode
 };
 
 
-#if IMF_HAVE_SSE2
+#ifdef IMF_HAVE_SSE2
 
 
 //------------------------------------------------------------------------
diff --git a/OpenEXR/IlmImf/ImfScanLineInputFile.cpp b/OpenEXR/IlmImf/ImfScanLineInputFile.cpp
index dcaa8c64df..35b5ed4d04 100644
--- a/OpenEXR/IlmImf/ImfScanLineInputFile.cpp
+++ b/OpenEXR/IlmImf/ImfScanLineInputFile.cpp
@@ -1264,7 +1264,7 @@ detectOptimizationMode (const vector<sliceOptimizationData>& optData)
     OptimizationMode w;
     
     // need to be compiled with SSE optimisations: if not, just returns false
-#if IMF_HAVE_SSE2
+#ifdef IMF_HAVE_SSE2
     
     
     // only handle reading 3,4,6 or 8 channels
diff --git a/OpenEXR/IlmImf/ImfSimd.h b/OpenEXR/IlmImf/ImfSimd.h
index 09b1042cb5..322d0905db 100644
--- a/OpenEXR/IlmImf/ImfSimd.h
+++ b/OpenEXR/IlmImf/ImfSimd.h
@@ -50,7 +50,7 @@
 
 extern "C"
 {
-#if IMF_HAVE_SSE2
+#ifdef IMF_HAVE_SSE2
     #include <emmintrin.h>
     #include <mmintrin.h>
 #endif