diff --git a/src/sbbs3/GNUmakefile b/src/sbbs3/GNUmakefile
index 458e1209e9906ad0425940cbf60a0ade66335233..bc99240f097e3449c0fdc53eeec743c6a42facc5 100644
--- a/src/sbbs3/GNUmakefile
+++ b/src/sbbs3/GNUmakefile
@@ -57,6 +57,8 @@ endif
 # this line wont work with solaris unless awk in path is actually gawk 
 os      :=	$(shell echo $(os) | tr "[A-Z]" "[a-z]")
 #os      :=	$(shell echo $(os) | awk '/.*/ { print tolower($$1)}')
+# remove '/' from "os/2"
+os      :=  $(shell echo $(os) | tr -d "/")
 
 ifeq ($(os),freebsd)
  BSD	=	1
diff --git a/src/sbbs3/scfg/GNUmakefile b/src/sbbs3/scfg/GNUmakefile
index 566f8c4b25ce100f5529834cdd3cd4fd35bc5aed..b2b5e061c16f2dac1e88b209becce39a25908b63 100644
--- a/src/sbbs3/scfg/GNUmakefile
+++ b/src/sbbs3/scfg/GNUmakefile
@@ -35,6 +35,8 @@ ifndef os
  $(warning OS not specified on command line, setting to '$(os)'.)
 endif
 os      :=	$(shell echo $(os) | tr "[A-Z]" "[a-z]")
+# remove '/' from "os/2"
+os      :=  $(shell echo $(os) | tr -d "/")
 
 ODIR	:=	gcc.$(os)
 
diff --git a/xtrn/sbj/GNUmakefile b/xtrn/sbj/GNUmakefile
index bb9794380aa89b70a26039647f9fae59864c3671..ef8cb7980ebfbbc31d571e8549dfa62debab41df 100644
--- a/xtrn/sbj/GNUmakefile
+++ b/xtrn/sbj/GNUmakefile
@@ -23,7 +23,10 @@ ifndef os
  os              =       $(shell uname)
  $(warning OS not specified on command line, setting to '$(os)'.)
 endif
-os      :=	$(shell echo $(os) | awk '/.*/ { print tolower($$1)}')
+os      :=	$(shell echo $(os) | tr "[A-Z]" "[a-z]")
+# remove '/' from "os/2"
+os      :=  $(shell echo $(os) | tr -d "/")
+
 
 LIBDIR	:=	/usr/lib
 DELETE	:=	rm -f -v
diff --git a/xtrn/sbl/GNUmakefile b/xtrn/sbl/GNUmakefile
index 6d23c4af1e8d082cb39dcd1cabadf306082d67fe..fd47105fcf58be0b3a82709831625f94adaa4243 100644
--- a/xtrn/sbl/GNUmakefile
+++ b/xtrn/sbl/GNUmakefile
@@ -29,7 +29,9 @@ ifndef os
  os              =       $(shell uname)
  $(warning OS not specified on command line, setting to '$(os)'.)
 endif
-os      :=	$(shell echo $(os) | awk '/.*/ { print tolower($$1)}')
+os      :=	$(shell echo $(os) | tr "[A-Z]" "[a-z]")
+# remove '/' from "os/2"
+os      :=  $(shell echo $(os) | tr -d "/")
 
 LIBDIR	:=	/usr/lib
 DELETE	:=	rm -f -v