diff --git a/scripts/runtests.in b/scripts/runtests.in
index 1841c93e9b7..296260618bc 100755
--- a/scripts/runtests.in
+++ b/scripts/runtests.in
@@ -26,6 +26,7 @@ if test @RUN_IN_PLACE@ = yes; then
     export HEADERS=@EMC2_HOME@/include
     export LIBDIR=${TOPDIR}/lib
     export INCLUDEPY=@INCLUDEPY@
+    export REALTIME=realtime
 else
     # Set $EMC2_HOME to $prefix for tests that depend on it
     export SYSTEM_BUILD=1
@@ -34,6 +35,7 @@ else
     export LIBDIR=@EMC2_HOME@/lib
     export INCLUDEPY=@INCLUDEPY@
     export LINUXCNC_EMCSH=@WISH@
+    export REALTIME=/etc/init.d/realtime
     export SUDO=sudo
 fi
 export INCLUDEPY=@INCLUDEPY@
diff --git a/tests/hal-link-unlink/test.sh b/tests/hal-link-unlink/test.sh
index 8f92654f56c..9f07c174918 100755
--- a/tests/hal-link-unlink/test.sh
+++ b/tests/hal-link-unlink/test.sh
@@ -1,8 +1,8 @@
 #!/bin/bash
 
-realtime start
+$REALTIME start
 linuxcnc-python hallink.py
 
-realtime stop
+$REALTIME stop
 
 exit $?
diff --git a/tests/halmodule.0/test.sh b/tests/halmodule.0/test.sh
index f815f73078d..2f7c479e233 100755
--- a/tests/halmodule.0/test.sh
+++ b/tests/halmodule.0/test.sh
@@ -1,4 +1,4 @@
 #!/bin/sh
-realtime start
+$REALTIME start
 ./test.py
-realtime stop
+$REALTIME stop
diff --git a/tests/save.0/test.sh b/tests/save.0/test.sh
index 0dccd8495e2..8ff3bdaa8ba 100644
--- a/tests/save.0/test.sh
+++ b/tests/save.0/test.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
-realtime start
+$REALTIME start
 halcmd -f expected
 halcmd save
 halcmd unload all
-realtime stop
+$REALTIME stop
diff --git a/tests/tclsh-extensions/test.sh b/tests/tclsh-extensions/test.sh
index 4f4aa08ebda..f30300c3744 100644
--- a/tests/tclsh-extensions/test.sh
+++ b/tests/tclsh-extensions/test.sh
@@ -2,7 +2,7 @@
 # (runtests needs to run without a display, but LINUXCNC_EMCSH is always a
 # wish-like program. Assume we can get the related non-wish interpreter in the
 # obvious way)
-realtime start
+$REALTIME start
 ${LINUXCNC_EMCSH/wish/tclsh} test.tcl; exitval=$?
-realtime stop
+$REALTIME stop
 exit $exitval