diff --git a/js/src/asmjs/Wasm.cpp b/js/src/asmjs/Wasm.cpp
index 468af1f9a25b..e7cdd53b6a7d 100644
--- a/js/src/asmjs/Wasm.cpp
+++ b/js/src/asmjs/Wasm.cpp
@@ -386,9 +386,6 @@ DecodeLoadStoreAddress(FunctionDecoder &f)
     if (!f.d().readVarU32(&offset))
         return f.fail("expected memory access offset");
 
-    if (offset != 0)
-        return f.fail("NYI: address offsets");
-
     uint32_t align;
     if (!f.d().readVarU32(&align))
         return f.fail("expected memory access alignment");
diff --git a/js/src/asmjs/WasmIonCompile.cpp b/js/src/asmjs/WasmIonCompile.cpp
index 345e25b89ed2..c279e9fdd7f4 100644
--- a/js/src/asmjs/WasmIonCompile.cpp
+++ b/js/src/asmjs/WasmIonCompile.cpp
@@ -1365,7 +1365,6 @@ static bool
 EmitHeapAddress(FunctionCompiler& f, MDefinition** base, MAsmJSHeapAccess* access)
 {
     uint32_t offset = f.readVarU32();
-    MOZ_ASSERT(offset == 0, "Non-zero offsets not supported yet");
     access->setOffset(offset);
 
     uint32_t align = f.readVarU32();
@@ -1374,13 +1373,24 @@ EmitHeapAddress(FunctionCompiler& f, MDefinition** base, MAsmJSHeapAccess* acces
     if (!EmitExpr(f, ExprType::I32, base))
         return false;
 
-    // TODO Remove this (and the viewType param) after implementing unaligned
-    // loads/stores.
     if (f.mg().isAsmJS()) {
         MOZ_ASSERT(offset == 0 && "asm.js validation does not produce load/store offsets");
         return true;
     }
 
+    // TODO Remove this after implementing non-wraparound offset semantics.
+    uint32_t endOffset = access->endOffset();
+    if (endOffset < offset)
+        return false;
+    bool accessNeedsBoundsCheck = true;
+    if (endOffset > f.mirGen().foldableOffsetRange(accessNeedsBoundsCheck)) {
+        MDefinition* rhs = f.constant(Int32Value(offset), MIRType_Int32);
+        *base = f.binary<MAdd>(*base, rhs, MIRType_Int32);
+        offset = 0;
+        access->setOffset(offset);
+    }
+
+    // TODO Remove this after implementing unaligned loads/stores.
     int32_t maskVal = ~(Scalar::byteSize(access->accessType()) - 1);
     if (maskVal == -1)
         return true;
diff --git a/js/src/jit-test/tests/wasm/basic-memory.js b/js/src/jit-test/tests/wasm/basic-memory.js
index 86728071c18f..39a6096b9d86 100644
--- a/js/src/jit-test/tests/wasm/basic-memory.js
+++ b/js/src/jit-test/tests/wasm/basic-memory.js
@@ -78,20 +78,20 @@ testLoad('i32', '', 0, 0, 0, 0x03020100);
 testLoad('i32', '', 1, 0, 0, 0x03020100);   // TODO: unaligned NYI
 //testLoad('i32', '', 1, 0, 0, 0x04030201); // TODO: unaligned NYI
 
-//testLoad('i32', '', 0, 1, 0, 0x01020304); // TODO: offsets NYI
-//testLoad('i32', '', 1, 1, 4, 0x02030405); // TODO: offsets NYI
+testLoad('i32', '', 0, 4, 0, 0x07060504);
+//testLoad('i32', '', 1, 3, 4, 0x07060504); // TODO: unaligned base NYI
 //testLoad('i64', '', 0, 0, 0, 0x0001020304050607); // TODO: i64 NYI
 //testLoad('i64', '', 1, 0, 0, 0x0102030405060708); // TODO: i64 NYI
 //testLoad('i64', '', 0, 1, 0, 0x0102030405060708); // TODO: i64 NYI
 //testLoad('i64', '', 1, 1, 4, 0x0203040506070809); // TODO: i64 NYI
 testLoad('f32', '', 0, 0, 0, 3.820471434542632e-37);
 //testLoad('f32', '', 1, 0, 0, 1.539989614439558e-36); // TODO: unaligned NYI
-//testLoad('f32', '', 0, 1, 0, 0x01020304); // TODO: offsets NYI
-//testLoad('f32', '', 1, 1, 4, 0x02030405); // TODO: offsets NYI
+testLoad('f32', '', 0, 4, 0, 1.0082513512365273e-34);
+//testLoad('f32', '', 1, 3, 4, 1.0082513512365273e-34); // TODO: unaligned base NYI
 testLoad('f64', '', 0, 0, 0, 7.949928895127363e-275);
 //testLoad('f64', '', 1, 0, 0, 5.447603722011605e-270); // TODO: unaligned NYI
-//testLoad('f64', '', 0, 1, 0, 0x01020304); // TODO: offsets NYI
-//testLoad('f64', '', 1, 1, 4, 0x02030405); // TODO: offsets NYI
+testLoad('f64', '', 0, 8, 0, 3.6919162048650923e-236);
+//testLoad('f64', '', 1, 7, 4, 3.6919162048650923e-236); // TODO: unaligned base NYI
 
 testLoad('i32', '8_s', 16, 0, 0, -0x10);
 testLoad('i32', '8_u', 16, 0, 0, 0xf0);
@@ -138,12 +138,12 @@ testStoreNYI('32');
 
 testStore('f32', '', 0, 0, 0, 0.01234566979110241);
 //testStore('f32', '', 1, 0, 0, 0.01234566979110241); // TODO: unaligned NYI
-//testStore('f32', '', 0, 1, 0, 0.01234567); // TODO: offsets NYI
-//testStore('f32', '', 1, 1, 4, 0.01234567); // TODO: offsets NYI
+testStore('f32', '', 0, 4, 0, 0.01234566979110241);
+//testStore('f32', '', 1, 3, 4, 0.01234566979110241); // TODO: unaligned base NYI
 testStore('f64', '', 0, 0, 0, 0.89012345);
 //testStore('f64', '', 1, 0, 0, 0.89012345); // TODO: unaligned NYI
-//testStore('f64', '', 0, 1, 0, 0.89012345); // TODO: offsets NYI
-//testStore('f64', '', 1, 1, 4, 0.89012345); // TODO: offsets NYI
+testStore('f64', '', 0, 8, 0, 0.89012345);
+testStore('f64', '', 1, 7, 4, 0.89012345);
 
 testStore('i32', '8', 0, 0, 0, 0x23);
 testStore('i32', '16', 0, 0, 0, 0x2345);