diff --git a/LOG b/LOG
index c21f0350ef..338572ad40 100644
--- a/LOG
+++ b/LOG
@@ -1359,3 +1359,5 @@
 - added MinGW/MSYS build support for Windows and configuration for
   Travis-CI testing of all Windows builds
     BUILDING, .travis*, wininstall/Makefile
+- fix multiply of -2^30 to itself on 64-bit platforms
+    number.c, 5_3.ms, release_notes.stex
diff --git a/c/number.c b/c/number.c
index 97bee865bd..4e39685fe0 100644
--- a/c/number.c
+++ b/c/number.c
@@ -637,9 +637,13 @@ static ptr big_mul(tc, x, y, xl, yl, sign) ptr tc, x, y; iptr xl, yl; IBOOL sign
   return copy_normalize(&BIGIT(W(tc),0),xl+yl,sign);
 }
 
-#define SHORTMIN (most_negative_fixnum / (1 << (fixnum_bits / 2)))
-#define SHORTMAX (most_positive_fixnum / (1 << (fixnum_bits / 2)))
-#define SHORTRANGE(x) ((x) >= SHORTMIN && (x) <= SHORTMAX)
+/* SHORTRANGE is -floor(sqrt(most_positive_fixnum))..floor(sqrt(most_positive_fixnum)).
+   We don't use sqrt because it rounds up for fixnum_bits = 61 */
+#if (fixnum_bits == 30)
+#define SHORTRANGE(x) (-23170 <= (x) && (x) <= 23170)
+#elif (fixnum_bits == 61)
+#define SHORTRANGE(x) (-0x3FFFFFFF <= (x) && (x) <= 0x3FFFFFFF)
+#endif
 
 ptr S_mul(x, y) ptr x, y; {
   ptr tc = get_thread_context();
diff --git a/mats/5_3.ms b/mats/5_3.ms
index e169c138c1..9a3296faa2 100644
--- a/mats/5_3.ms
+++ b/mats/5_3.ms
@@ -1599,6 +1599,30 @@
     (error? (* 'a 3 4))
     (error? (* 3 5 'a 4))
     (eqv? (* 1 2) 2)
+    (eqv? (* 23170 23170) 536848900)
+    (eqv? (* 23170 -23170) -536848900)
+    (eqv? (* -23170 23170) -536848900)
+    (eqv? (* -23170 -23170) 536848900)
+    (eqv? (* 23171 23170) 536872070)
+    (eqv? (* 23171 -23170) -536872070)
+    (eqv? (* -23171 23170) -536872070)
+    (eqv? (* -23171 -23170) 536872070)
+    (eqv? (* 23171 23171) 536895241)
+    (eqv? (* 23171 -23171) -536895241)
+    (eqv? (* -23171 23171) -536895241)
+    (eqv? (* -23171 -23171) 536895241)
+    (eqv? (* #x3FFFFFFF #x3FFFFFFF) #xFFFFFFF80000001)
+    (eqv? (* #x3FFFFFFF #x-3FFFFFFF) #x-FFFFFFF80000001)
+    (eqv? (* #x-3FFFFFFF #x3FFFFFFF) #x-FFFFFFF80000001)
+    (eqv? (* #x-3FFFFFFF #x-3FFFFFFF) #xFFFFFFF80000001)
+    (eqv? (* #x40000000 #x3FFFFFFF) #xFFFFFFFC0000000)
+    (eqv? (* #x40000000 #x-3FFFFFFF) #x-FFFFFFFC0000000)
+    (eqv? (* #x-40000000 #x3FFFFFFF) #x-FFFFFFFC0000000)
+    (eqv? (* #x-40000000 #x-3FFFFFFF) #xFFFFFFFC0000000)
+    (eqv? (* #x40000000 #x40000000) #x1000000000000000)
+    (eqv? (* #x40000000 #x-40000000) #x-1000000000000000)
+    (eqv? (* #x-40000000 #x40000000) #x-1000000000000000)
+    (eqv? (* #x-40000000 #x-40000000) #x1000000000000000)
     (fl~= (* 1.0 2) 2.0)
     (fl~= (* 1 2.0) 2.0)
     (eqv? (* 3/5 2/5) 6/25)
diff --git a/release_notes/release_notes.stex b/release_notes/release_notes.stex
index d28f060243..bf544ed770 100644
--- a/release_notes/release_notes.stex
+++ b/release_notes/release_notes.stex
@@ -1695,6 +1695,11 @@ in fasl files does not generally make sense.
 %-----------------------------------------------------------------------------
 \section{Bug Fixes}\label{section:bugfixes}
 
+\subsection{Muliplication of $-2^{30}$ by itself on 64-bit platforms (9.5.3)}
+
+A bug that produced the wrong sign when multiplying $-2^{30}$ by
+itself on 64-bit platforms has been fixed.
+
 \subsection{Compiler dropping affects from record-accessor calls (9.5.3)}
 
 A bug that could cause the source optimizer to drop effects within