diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java b/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
index a257dc2ce..abd488e03 100644
--- a/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
+++ b/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
@@ -486,6 +486,7 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                         .nullValuePropertyMappingStrategy( mapping.getNullValuePropertyMappingStrategy() )
                         .build();
                     handledTargets.add( propertyName );
+                    unprocessedSourceProperties.remove( mapping.getSourceName() );
                     unprocessedSourceParameters.remove( sourceRef.getParameter() );
                 }
                 else {
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Issue1648Mapper.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Issue1648Mapper.java
new file mode 100644
index 000000000..713de8699
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Issue1648Mapper.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._1648;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.ReportingPolicy;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper(unmappedSourcePolicy = ReportingPolicy.ERROR)
+public interface Issue1648Mapper {
+
+    Issue1648Mapper INSTANCE = Mappers.getMapper( Issue1648Mapper.class );
+
+    @Mapping(target = "targetValue", source = "sourceValue")
+    Target map(Source source);
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Issue1648Test.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Issue1648Test.java
new file mode 100644
index 000000000..03ba02d4b
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Issue1648Test.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._1648;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Filip Hrisafov
+ */
+@IssueKey("1648")
+@RunWith(AnnotationProcessorTestRunner.class)
+@WithClasses({
+    Issue1648Mapper.class,
+    Source.class,
+    Target.class,
+})
+public class Issue1648Test {
+
+    @Test
+    public void shouldCorrectlyMarkSourceAsUsed() {
+        Source source = new Source();
+        source.setSourceValue( "value" );
+
+        Target target = Issue1648Mapper.INSTANCE.map( source );
+
+        assertThat( target.getTargetValue() ).isEqualTo( "value" );
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Source.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Source.java
new file mode 100644
index 000000000..5d9f207bf
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Source.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._1648;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class Source {
+
+    private String sourceValue;
+
+    public String getSourceValue() {
+        return sourceValue;
+    }
+
+    public void setSourceValue(String sourceValue) {
+        this.sourceValue = sourceValue;
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Target.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Target.java
new file mode 100644
index 000000000..0225e9540
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_1648/Target.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._1648;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class Target {
+
+    private String targetValue;
+
+    public String getTargetValue() {
+        return targetValue;
+    }
+
+    public void setTargetValue(String targetValue) {
+        this.targetValue = targetValue;
+    }
+}