diff --git a/Makefile.linux b/Makefile.linux
index 1bbaf12ca..13ef0fb05 100644
--- a/Makefile.linux
+++ b/Makefile.linux
@@ -83,6 +83,10 @@ $(OBJDIR)/%.o: %.nas
 $(OBJDIR)/nodebuild_classify_sse2.o: nodebuild_classify_sse2.cpp
 	$(CCDV) $(CXX) $(CXXFLAGS) -msse2 -mfpmath=sse -c -o $@ $<
 
+# This file needs special handling because GCC misoptimizes it otherwise.
+$(OBJDIR)/fmopl.o: src/oplsynth/fmopl.cpp
+	$(CCDV) $(CXX) $(CXXFLAGS) -fno-tree-dominator-opts -fno-tree-fre -c -o $@ $<
+
 $(OBJDIR):
 	mkdir $(OBJDIR)
 
diff --git a/Makefile.mingw b/Makefile.mingw
index 6d8640892..dd20aea9c 100644
--- a/Makefile.mingw
+++ b/Makefile.mingw
@@ -83,6 +83,10 @@ all: $(TARGET)
 $(OBJDIR)/nodebuild_classify_sse2.o: src/nodebuild_classify_sse2.cpp
 	$(CCDV) $(CXX) $(CXXFLAGS) -msse2 -mfpmath=sse -c -o $@ $<
 
+# This file needs special handling because GCC misoptimizes it otherwise.
+$(OBJDIR)/fmopl.o: src/oplsynth/fmopl.cpp
+	$(CCDV) $(CXX) $(CXXFLAGS) -fno-tree-dominator-opts -fno-tree-fre -c -o $@ $<
+
 src/sc_man_scanner.h: src/sc_man_scanner.re
 	$(CCDV) $(RE2C) -s -o $@ $<
 
diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index fc5e9376c..f10a6faea 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,6 @@
 February 5, 2008
+- Updated the GCC-targeted makefiles to turn off two optimizations that cause
+  fmopl.cpp to compile incorrectly: tree-dominator-opts and tree-fre
 - Fixed: Morphed pig and chicken players made normal human *usefail sounds.
 - G_DoSaveGame() now receives the filename and description from its arguments
   rather than global variables, so autosaves and manual saves can be done