diff --git a/mach/mips/libem/set.s b/mach/mips/libem/set.s
index 01a6ff654..ec45eb45a 100644
--- a/mach/mips/libem/set.s
+++ b/mach/mips/libem/set.s
@@ -11,23 +11,25 @@
 .set:
 	lw r4, 0(sp)        ! r4 = size
 	lw r5, 4(sp)        ! r5 = bit number
-	addiu sp, sp, 4
+	addiu sp, sp, 8
 	srl r4, r4, 2       ! r4 = word count
 
-	! Create an empty set.
+	! Create an empty set by pushing zeros.
 
 1:
 	addiu sp, sp, -4
 	sw zero, 0(sp)
 	addiu r4, r4, -1
 	bne r4, zero, 1b
+	nop
 
 	! sp now points at the set.
 
-	srl r6, r5, 3       ! r6 = offset of word in set
-	addu r6, sp, r6     ! r6 = address of word in set
+	andi r6, r5, ~31	! r6 = bit offset of base of word in set
+	srl r6,r6, 3        ! r6 = byte offset of word in set
+	addu r6, sp, r6		! r6 = address of word in set
 
-	ext r7, r5, 0, 3    ! r7 = bit number within word
+	andi r7, r5, 31		! r7 = bit number within word
 	li r8, 1
 	sllv r8, r8, r7     ! r8 = word with 1 set
 	sw r8, 0(r6)        ! write to set
diff --git a/tests/plat/core/set_e.e b/tests/plat/core/set_e.e
new file mode 100644
index 000000000..55659a3de
--- /dev/null
+++ b/tests/plat/core/set_e.e
@@ -0,0 +1,50 @@
+#
+    mes 2, EM_WSIZE, EM_PSIZE
+
+    exp $_m_a_i_n
+    pro $_m_a_i_n, 0
+
+	/* Create word-sized singleton set. */
+
+word
+	rom EM_WSIZE
+
+	loc 1
+	loe word		/* to defeat constant folding */
+	set
+
+	loc 2
+	cmu EM_WSIZE
+	zeq *1
+
+    loc __LINE__
+    cal $fail
+    asp 4
+1
+
+	/* Create triple-word-sized set with low bit */
+
+	loc EM_WSIZE*8 + 1
+	loe word		/* to defeat constant folding */
+	loc 3
+	mli EM_WSIZE
+	set
+
+
+	loc 0
+	cmu EM_WSIZE
+	zne *2
+	loc 2
+	cmu EM_WSIZE
+	zne *2
+	loc 0
+	cmu EM_WSIZE
+	zeq *3
+2
+	loc __LINE__
+	cal $fail
+	asp 4
+3
+
+    cal $finished
+    end
diff --git a/tests/plat/lib/test.c b/tests/plat/lib/test.c
index 6df3ee7d5..33a4e86e7 100644
--- a/tests/plat/lib/test.c
+++ b/tests/plat/lib/test.c
@@ -9,7 +9,7 @@ void finished(void)
     _exit(0);
 }
 
-void writehex(uint32_t code)
+void writehex(unsigned int code)
 {
     char buf[8];
     char* p = &buf[sizeof(buf)];
@@ -24,7 +24,7 @@ void writehex(uint32_t code)
     write(1, p, buf + sizeof(buf) - p);
 }
 
-void fail(uint32_t code)
+void fail(unsigned int code)
 {
     static const char fail_msg[] = "@@FAIL 0x";
     static const char nl_msg[] = "\n";
diff --git a/tests/plat/lib/test.h b/tests/plat/lib/test.h
index db16506f9..6c0acc6b2 100644
--- a/tests/plat/lib/test.h
+++ b/tests/plat/lib/test.h
@@ -5,8 +5,8 @@
 #include <stdint.h>
 
 extern void finished(void);
-extern void writehex(uint32_t code);
-extern void fail(uint32_t code);
+extern void writehex(unsigned int code);
+extern void fail(unsigned int code);
 
 #define ASSERT(condition) \
     do { if (!(condition)) fail(__LINE__); } while(0)