diff --git a/documentation/RELEASE_NOTES.html b/documentation/RELEASE_NOTES.html
index b341d7e98..32314d431 100644
--- a/documentation/RELEASE_NOTES.html
+++ b/documentation/RELEASE_NOTES.html
@@ -12,6 +12,11 @@
 <h2 align="center">Changes between 3.14.10 and 3.14.11</h2>
 <!-- Insert new items below here ... -->
 
+<h4>New math constants epicsNAN and epicsINF</h4>
+
+<p>Two new math constants have been added to epicsMath.h: <tt>epicsNAN</tt>
+(not a number) and <tt>epicsINF</tt> (infinity).
+
 <h4>New event type DBE_PROPERTY</h4>
 
 <p>A new event type (flag in the Channel Access event mask) has been added
diff --git a/src/libCom/Makefile b/src/libCom/Makefile
index a7c1f3ccb..3d251f35c 100644
--- a/src/libCom/Makefile
+++ b/src/libCom/Makefile
@@ -199,6 +199,7 @@ SRCS += epicsMutex.cpp
 SRCS += epicsEvent.cpp
 SRCS += epicsTime.cpp
 SRCS += epicsMessageQueue.cpp
+SRCS += epicsMath.cpp
 
 SRCS += epicsGeneralTime.c
 SRCS += osiClockTime.c
diff --git a/src/libCom/osi/os/Darwin/epicsMath.h b/src/libCom/osi/os/Darwin/epicsMath.h
index 4c580e68b..6dd2b87e1 100644
--- a/src/libCom/osi/os/Darwin/epicsMath.h
+++ b/src/libCom/osi/os/Darwin/epicsMath.h
@@ -7,11 +7,16 @@
 * and higher are distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution. 
 \*************************************************************************/
+
 #ifndef epicsMathh
 #define epicsMathh
 
 #include <math.h>
+#include <shareLib.h>
 
 #define finite(x) isfinite(x)
 
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
+
 #endif /* epicsMathh */
diff --git a/src/libCom/osi/os/RTEMS/epicsMath.h b/src/libCom/osi/os/RTEMS/epicsMath.h
index be7005b6b..aeb5132be 100644
--- a/src/libCom/osi/os/RTEMS/epicsMath.h
+++ b/src/libCom/osi/os/RTEMS/epicsMath.h
@@ -7,10 +7,15 @@
 * and higher are distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution. 
 \*************************************************************************/
+
 #ifndef epicsMathh
 #define epicsMathh
 
 #include <math.h>
 #include <ieeefp.h>
+#include <shareLib.h>
+
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
 
 #endif /* epicsMathh */
diff --git a/src/libCom/osi/os/VMS/epicsMath.h b/src/libCom/osi/os/VMS/epicsMath.h
index 40b7d2a83..df8fba67b 100644
--- a/src/libCom/osi/os/VMS/epicsMath.h
+++ b/src/libCom/osi/os/VMS/epicsMath.h
@@ -7,10 +7,16 @@
 * and higher are distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution. 
 \*************************************************************************/
+
 #ifndef epicsMathh
 #define epicsMathh
 
 #include <math.h>
+#include <shareLib.h>
+
 #define isinf(D) (!finite((D)) && !(isnan((D))))
 
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
+
 #endif /* epicsMathh */
diff --git a/src/libCom/osi/os/WIN32/epicsMath.h b/src/libCom/osi/os/WIN32/epicsMath.h
index 99580be03..f9da1502b 100644
--- a/src/libCom/osi/os/WIN32/epicsMath.h
+++ b/src/libCom/osi/os/WIN32/epicsMath.h
@@ -13,6 +13,7 @@
 
 #include <math.h>
 #include <float.h>
+#include <shareLib.h>
 
 #ifndef finite
 #define finite(D) _finite(D)
@@ -26,4 +27,7 @@
 #define isinf(D) ( !_finite(D) && !_isnan(D) ) 
 #endif
 
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
+
 #endif /* epicsMathh */
diff --git a/src/libCom/osi/os/hpux/epicsMath.h b/src/libCom/osi/os/hpux/epicsMath.h
index 7e6b2f46f..f1a8cb7c4 100644
--- a/src/libCom/osi/os/hpux/epicsMath.h
+++ b/src/libCom/osi/os/hpux/epicsMath.h
@@ -12,7 +12,11 @@
 #define epicsMathh
 
 #include <math.h>
+#include <shareLib.h>
 
 #define finite(D) (isfinite(D) != 0)
 
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
+
 #endif /* epicsMathh */
diff --git a/src/libCom/osi/os/osf/epicsMath.h b/src/libCom/osi/os/osf/epicsMath.h
index 40b7d2a83..df8fba67b 100644
--- a/src/libCom/osi/os/osf/epicsMath.h
+++ b/src/libCom/osi/os/osf/epicsMath.h
@@ -7,10 +7,16 @@
 * and higher are distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution. 
 \*************************************************************************/
+
 #ifndef epicsMathh
 #define epicsMathh
 
 #include <math.h>
+#include <shareLib.h>
+
 #define isinf(D) (!finite((D)) && !(isnan((D))))
 
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
+
 #endif /* epicsMathh */
diff --git a/src/libCom/osi/os/posix/epicsMath.h b/src/libCom/osi/os/posix/epicsMath.h
index 848b375ee..095062f9c 100644
--- a/src/libCom/osi/os/posix/epicsMath.h
+++ b/src/libCom/osi/os/posix/epicsMath.h
@@ -7,9 +7,14 @@
 * and higher are distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution. 
 \*************************************************************************/
+
 #ifndef epicsMathh
 #define epicsMathh
 
 #include <math.h>
+#include <shareLib.h>
+
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
 
 #endif /* epicsMathh */
diff --git a/src/libCom/osi/os/solaris/epicsMath.h b/src/libCom/osi/os/solaris/epicsMath.h
index 0f714acde..41176401e 100644
--- a/src/libCom/osi/os/solaris/epicsMath.h
+++ b/src/libCom/osi/os/solaris/epicsMath.h
@@ -4,16 +4,20 @@
 * EPICS BASE is distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution. 
 \*************************************************************************/
+
 #ifndef INC_epicsMath_H
 #define INC_epicsMath_H
 
 #include <math.h>
-
 #include <ieeefp.h>
+#include <shareLib.h>
 
 #ifndef isinf
 #  define isinf(x) (((x)==(x)) && !finite((x)))
 /* same as (!isnan(x) && !finite(x)) */
 #endif
 
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
+
 #endif /* INC_epicsMath_H */
diff --git a/src/libCom/osi/os/vxWorks/epicsMath.h b/src/libCom/osi/os/vxWorks/epicsMath.h
index eddb756f8..acd607491 100644
--- a/src/libCom/osi/os/vxWorks/epicsMath.h
+++ b/src/libCom/osi/os/vxWorks/epicsMath.h
@@ -13,9 +13,13 @@
 
 #include <math.h>
 #include <private/mathP.h>
+#include <shareLib.h>
 
 #define isnan(D) isNan(D)
 #define isinf(D) isInf(D)
 #define finite(D) (!isNan(D) && !isInf(D))
 
+epicsShareExtern float epicsNAN;
+epicsShareExtern float epicsINF;
+
 #endif /* epicsMathh */
diff --git a/src/libCom/test/epicsMathTest.c b/src/libCom/test/epicsMathTest.c
index ab7a633fd..4879bea01 100644
--- a/src/libCom/test/epicsMathTest.c
+++ b/src/libCom/test/epicsMathTest.c
@@ -28,9 +28,7 @@ MAIN(epicsMathTest)
     testOk(!isinf(c), "!isinf(0.0 / 1.0)");
     testOk(c == 0.0, "0.0 / 1.0 == 0.0");
     
-    a = 1.0;
-    b = 0.0;
-    c = a / b;
+    c = epicsINF;
     testOk(!isnan(c), "!isnan(1.0 / 0.0)");
     testOk(isinf(c), "isinf(1.0 / 0.0)");
     testOk(c == c, "1.0 / 0.0 == 1.0 / 0.0");
@@ -38,9 +36,7 @@ MAIN(epicsMathTest)
     testOk(c + -c != b, "inf + -inf != 0");
     testOk(-c + c != b, "-inf + inf != 0");
     
-    a = 0.0;
-    b = 0.0;
-    c = a / b;
+    c = epicsNAN;
     testOk(isnan(c), "isnan(0.0 / 0.0)");
     testOk(!isinf(c), "!isinf(0.0 / 0.0)");
     testOk(c != c, "0.0 / 0.0 != 0.0 / 0.0");