diff --git a/src/avian/common.h b/src/avian/common.h
index 4fad202fe4..f8a0e22168 100644
--- a/src/avian/common.h
+++ b/src/avian/common.h
@@ -27,6 +27,14 @@
 
 #include "float.h"
 
+#ifdef powerpc
+#  undef powerpc
+#endif
+
+#ifdef linux
+#  undef linux
+#endif
+
 // don't complain about using 'this' in member initializers:
 #  pragma warning(disable:4355)
 
diff --git a/src/codegen/target/powerpc/context.h b/src/codegen/target/powerpc/context.h
index 4e12f4882c..7726b88cf5 100644
--- a/src/codegen/target/powerpc/context.h
+++ b/src/codegen/target/powerpc/context.h
@@ -14,6 +14,9 @@
 #include <avian/vm/codegen/assembler.h>
 #include "avian/alloc-vector.h"
 
+#ifdef powerpc
+#undef powerpc
+#endif
 
 namespace vm {
 class System;
diff --git a/src/codegen/target/powerpc/encode.h b/src/codegen/target/powerpc/encode.h
index 54f7f7f493..811ddce402 100644
--- a/src/codegen/target/powerpc/encode.h
+++ b/src/codegen/target/powerpc/encode.h
@@ -11,6 +11,10 @@
 #ifndef AVIAN_CODEGEN_ASSEMBLER_POWERPC_ENCODE_H
 #define AVIAN_CODEGEN_ASSEMBLER_POWERPC_ENCODE_H
 
+#ifdef powerpc
+#undef powerpc
+#endif
+
 namespace avian {
 namespace codegen {
 namespace powerpc {