diff --git a/src/configure b/src/configure
index df221e0205..ebf67615f3 100755
--- a/src/configure
+++ b/src/configure
@@ -4095,7 +4095,7 @@ case "$host_os" in
     ;;
   nto-qnx*)
     enable_sgc=yes
-    LIBS="$LIBS -lsocket"
+    LIBS="$LIBS -lsocket -Wl,--export-dynamic"
     ;;
   *)
     ;;
diff --git a/src/racket/configure.ac b/src/racket/configure.ac
index ce38b3eba7..01b98c23ba 100644
--- a/src/racket/configure.ac
+++ b/src/racket/configure.ac
@@ -627,7 +627,7 @@ case "$host_os" in
     ;;
   nto-qnx*)
     enable_sgc=yes
-    LIBS="$LIBS -lsocket"
+    LIBS="$LIBS -lsocket -Wl,--export-dynamic"
     ;;
   *)
     ;;
diff --git a/src/racket/sconfig.h b/src/racket/sconfig.h
index 0fa7708a8f..bf110ef2e4 100644
--- a/src/racket/sconfig.h
+++ b/src/racket/sconfig.h
@@ -940,6 +940,8 @@
 #if defined(__QNX__)
 # define USE_FCNTL_O_NONBLOCK
 # define SCHEME_PLATFORM_LIBRARY_SUBPATH "i386-QNX"
+# define ASSUME_FIXED_STACK_SIZE
+# define FIXED_STACK_SIZE 524288
 #endif
 
 /************** (END KNOWN ARCHITECTURE/SYSTEMS) ****************/