diff --git a/software/libbase/Makefile b/software/libbase/Makefile
index 35f92f659..c1f2434df 100644
--- a/software/libbase/Makefile
+++ b/software/libbase/Makefile
@@ -1,7 +1,7 @@
 MSCDIR=../..
 include $(MSCDIR)/software/common.mak
 
-OBJECTS=exception.o libc.o errno.o crc16.o crc32.o console.o environ.o system.o id.o uart.o time.o qsort.o strtod.o spiflash.o
+OBJECTS=exception.o libc.o errno.o crc16.o crc32.o console.o system.o id.o uart.o time.o qsort.o strtod.o spiflash.o
 
 all: crt0-$(CPU).o libbase.a libbase-nofloat.a
 
diff --git a/software/libbase/environ.c b/software/libbase/environ.c
deleted file mode 100644
index 2c2c92f08..000000000
--- a/software/libbase/environ.c
+++ /dev/null
@@ -1,11 +0,0 @@
-#include <stdlib.h>
-#include <string.h>
-
-char *getenv(const char *varname) {
-  if(!strcmp(varname, "LIBUNWIND_PRINT_APIS") ||
-     !strcmp(varname, "LIBUNWIND_PRINT_UNWINDING")) {
-    return "1";
-  } else {
-    return NULL;
-  }
-}
diff --git a/software/libunwind/Makefile b/software/libunwind/Makefile
index f250db79d..899eff434 100644
--- a/software/libunwind/Makefile
+++ b/software/libunwind/Makefile
@@ -3,7 +3,7 @@ include $(MSCDIR)/software/common.mak
 
 COMMONFLAGS+=-integrated-as \
 	-I. -I$(MSCDIR)/software/include/dyld/ -I$(MSCDIR)/software/unwinder/include/ \
-	-D__ELF__ -D__linux__
+	-D__ELF__ -D__linux__ -D_LIBUNWIND_NO_HEAP
 
 OBJECTS=UnwindRegistersSave.o UnwindRegistersRestore.o UnwindLevel1.o libunwind.o
 
diff --git a/software/unwinder b/software/unwinder
index 70a7d2ad4..2f26626b6 160000
--- a/software/unwinder
+++ b/software/unwinder
@@ -1 +1 @@
-Subproject commit 70a7d2ad43da6ebf9113b0101bfd4b202e0c7b6b
+Subproject commit 2f26626b6bdc17a2fcb0aeec7a9135d0c7409661