diff --git a/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/MatMult.java b/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/MatMult.java
index b493cfcbd39bfb2dbbcd38812164ad77ce869501..589e4cf028ed66e5fbe43a67a1e0d081485426e4 100644
--- a/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/MatMult.java
+++ b/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/MatMult.java
@@ -371,7 +371,7 @@ public abstract class MatMult extends RBuiltinNode {
                             na.check(x);
                         }
                         result[row << 1] = x.getRealPart();
-                        result[row << 1 + 1] = x.getImaginaryPart();
+                        result[(row << 1) + 1] = x.getImaginaryPart();
                     }
                     return RDataFactory.createComplexVector(result, na.neverSeenNA(), new int[]{aRows, 1});
                 } else {
@@ -381,7 +381,7 @@ public abstract class MatMult extends RBuiltinNode {
                             RComplex x = mult.applyComplex(a.getDataAt(row), b.getDataAt(k));
                             na.check(x);
                             result[(k * aRows + row) << 1] = x.getRealPart();
-                            result[(k * aRows + row) << 1 + 1] = x.getRealPart();
+                            result[((k * aRows + row) << 1) + 1] = x.getRealPart();
                         }
                     }
                     return RDataFactory.createComplexVector(result, na.neverSeenNA(), new int[]{aRows, b.getLength()});
@@ -406,7 +406,7 @@ public abstract class MatMult extends RBuiltinNode {
                             na.check(x);
                         }
                         result[k << 1] = x.getRealPart();
-                        result[k << 1 + 1] = x.getImaginaryPart();
+                        result[(k << 1) + 1] = x.getImaginaryPart();
                     }
                     return RDataFactory.createComplexVector(result, na.neverSeenNA(), new int[]{1, bCols});
                 } else {
@@ -416,7 +416,7 @@ public abstract class MatMult extends RBuiltinNode {
                             RComplex x = mult.applyComplex(a.getDataAt(row), b.getDataAt(k));
                             na.check(x);
                             result[(k * a.getLength() + row) << 1] = x.getRealPart();
-                            result[(k * a.getLength() + row) << 1 + 1] = x.getImaginaryPart();
+                            result[((k * a.getLength() + row) << 1) + 1] = x.getImaginaryPart();
                         }
                     }
                     return RDataFactory.createComplexVector(result, na.neverSeenNA(), new int[]{a.getLength(), bCols});
diff --git a/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/Unique.java b/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/Unique.java
index 08f16b42541c32820bbfb58aac92904ae69a25e4..74c3cda1adc2acb91fe46584ee1a18ab30fe37f3 100644
--- a/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/Unique.java
+++ b/com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/Unique.java
@@ -176,7 +176,7 @@ public abstract class Unique extends RBuiltinNode {
 
         public boolean contains(RComplex val) {
             for (int i = 0; i < index; i++) {
-                if (backingArray[i << 1] == val.getRealPart() && backingArray[i << 1 + 1] == val.getImaginaryPart()) {
+                if (backingArray[i << 1] == val.getRealPart() && backingArray[(i << 1) + 1] == val.getImaginaryPart()) {
                     return true;
                 }
             }
diff --git a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_operators.java b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_operators.java
index 5599bc8cc873e7227e5d34731421625417c49e0b..47e17724e82ff67fe1bed273551f39493b9ae00b 100644
--- a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_operators.java
+++ b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_operators.java
@@ -1955,8 +1955,8 @@ public class TestBuiltin_operators extends TestBase {
         assertEval("{ c(1+1i,2-2i,3+3i) %*% c(4-4i,5+5i,6-6i) }");
         assertEval("{ matrix(c(1+1i,0-0i,4+4i),3) %*% matrix(c(3+3i,1-1i,2+2i,0-0i,1+1i,2-2i),1) }");
 
-        assertEval(Ignored.Unknown, "{ matrix(c(3+3i,1-1i,2+2i,0-0i,1+1i,2-2i),2) %*% c(1+1i,0-0i,4+4i) }");
-        assertEval(Ignored.Unknown, "{ c(1+1i,0-0i,4+4i) %*% matrix(c(3+3i,1-1i,2+2i,0-0i,1+1i,2-2i),3) }");
+        assertEval("{ matrix(c(3+3i,1-1i,2+2i,0-0i,1+1i,2-2i),2) %*% c(1+1i,0-0i,4+4i) }");
+        assertEval("{ c(1+1i,0-0i,4+4i) %*% matrix(c(3+3i,1-1i,2+2i,0-0i,1+1i,2-2i),3) }");
     }
 
     @Test