diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index a78f756..9c11aa0 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -173,6 +173,10 @@
 # We're on Windows NT or using VC 6+
 ! ifdef CPU
 ASSEMBLY_ARCHITECTURE=$(CPU)
+# Using I386 for $ASSEMBLY_ARCHITECTURE doesn't work for VC7.
+!  if ("$(ASSEMBLY_ARCHITECTURE)" == "i386") || ("$(ASSEMBLY_ARCHITECTURE)" == "I386")
+ASSEMBLY_ARCHITECTURE = x86
+!  endif
 ! else
 CPU = $(PROCESSOR_ARCHITECTURE)
 ASSEMBLY_ARCHITECTURE = $(PROCESSOR_ARCHITECTURE)