diff --git a/Makefile.in b/Makefile.in
index e1b5a4903c87..730fbc998545 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -280,6 +280,13 @@ tier_99_dirs += embedding/tests
 endif
 endif
 
+# os2embed
+ifeq ($(OS_ARCH),OS2)
+ifneq (,$(ENABLE_TESTS)$(MOZILLA_OFFICIAL))
+tier_99_dirs += embedding/tests
+endif
+endif
+
 else
 
 # Standalone build
diff --git a/embedding/base/Makefile.in b/embedding/base/Makefile.in
index 44b91a771785..ba17ecaa1bf6 100644
--- a/embedding/base/Makefile.in
+++ b/embedding/base/Makefile.in
@@ -62,6 +62,10 @@ ifeq ($(OS_ARCH),WINNT)
 CPPSRCS		+= nsEmbedWin32.cpp
 endif
 
+ifeq ($(OS_ARCH),OS2)
+CPPSRCS		+= nsEmbedOS2.cpp
+endif
+
 # we don't want the shared lib, but we want to force the creation of a
 # static lib.
 FORCE_STATIC_LIB = 1
diff --git a/embedding/tests/Makefile.in b/embedding/tests/Makefile.in
index 50f9d00baeb1..4322f2c9a9d2 100644
--- a/embedding/tests/Makefile.in
+++ b/embedding/tests/Makefile.in
@@ -24,6 +24,11 @@ VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
+ifeq ($(OS_ARCH),OS2)
+DIRS = os2Embed
+endif
+
+ifeq ($(OS_ARCH),WINNT)
 DIRS = winEmbed
 
 ifndef GNU_CC
@@ -31,5 +36,6 @@ ifndef NO_MFC
 DIRS += mfcembed/components mfcembed
 endif
 endif
+endif
 
 include $(topsrcdir)/config/rules.mk