diff --git a/src/sksl/dsl/DSLFunction.cpp b/src/sksl/dsl/DSLFunction.cpp
index 6eafc99..8bd93ad 100644
--- a/src/sksl/dsl/DSLFunction.cpp
+++ b/src/sksl/dsl/DSLFunction.cpp
@@ -12,6 +12,7 @@
 #include "src/sksl/SkSLCompiler.h"
 #include "src/sksl/SkSLIRGenerator.h"
 #include "src/sksl/dsl/priv/DSLWriter.h"
+#include "src/sksl/ir/SkSLFunctionPrototype.h"
 #include "src/sksl/ir/SkSLReturnStatement.h"
 
 namespace SkSL {
@@ -60,6 +61,11 @@
         for (size_t i = 0; i < params.size(); ++i) {
             params[i]->fVar = fDecl->parameters()[i];
         }
+        // We don't know when this function is going to be defined; go ahead and add a prototype in
+        // case the definition is delayed. If we end up defining the function immediately, we'll
+        // remove the prototype in define().
+        DSLWriter::ProgramElements().push_back(std::make_unique<SkSL::FunctionPrototype>(
+                /*offset=*/-1, fDecl, DSLWriter::IsModule()));
     }
 }
 
@@ -70,6 +76,17 @@
         block.release();
         return;
     }
+    if (!DSLWriter::ProgramElements().empty()) {
+        // If the last ProgramElement was the prototype for this function, it was unnecessary and we
+        // can remove it.
+        const SkSL::ProgramElement& last = *DSLWriter::ProgramElements().back();
+        if (last.is<SkSL::FunctionPrototype>()) {
+            const SkSL::FunctionPrototype& prototype = last.as<SkSL::FunctionPrototype>();
+            if (&prototype.declaration() == fDecl) {
+                DSLWriter::ProgramElements().pop_back();
+            }
+        }
+    }
     SkASSERTF(!fDecl->definition(), "function '%s' already defined", fDecl->description().c_str());
     std::unique_ptr<Block> body = block.release();
     body = DSLWriter::IRGenerator().finalizeFunction(*fDecl, std::move(body));
diff --git a/tests/SkSLDSLTest.cpp b/tests/SkSLDSLTest.cpp
index 94095f7..8e1bfd2 100644
--- a/tests/SkSLDSLTest.cpp
+++ b/tests/SkSLDSLTest.cpp
@@ -2051,3 +2051,45 @@
     // Ensure that we can safely destroy statements and expressions despite being unused while
     // settings.fAssertDSLObjectsReleased is disabled.
 }
+
+DEF_GPUTEST_FOR_MOCK_CONTEXT(DSLPrototypes, r, ctxInfo) {
+    AutoDSLContext context(ctxInfo.directContext()->priv().getGpu(), no_mark_vars_declared());
+    {
+        DSLParameter x(kFloat_Type, "x");
+        DSLFunction sqr(kFloat_Type, "sqr", x);
+        REPORTER_ASSERT(r, DSLWriter::ProgramElements().size() == 1);
+        EXPECT_EQUAL(*DSLWriter::ProgramElements()[0], "float sqr(float x);");
+        sqr.define(
+            Return(x * x)
+        );
+        REPORTER_ASSERT(r, DSLWriter::ProgramElements().size() == 1);
+        EXPECT_EQUAL(*DSLWriter::ProgramElements()[0], "float sqr(float x) { return (x * x); }");
+    }
+
+    {
+        DSLWriter::Reset();
+            DSLParameter x(kFloat_Type, "x");
+        DSLFunction sqr(kFloat_Type, "sqr", x);
+        REPORTER_ASSERT(r, DSLWriter::ProgramElements().size() == 1);
+        EXPECT_EQUAL(*DSLWriter::ProgramElements()[0], "float sqr(float x);");
+        DSLFunction(kVoid_Type, "main").define(sqr(5));
+        REPORTER_ASSERT(r, DSLWriter::ProgramElements().size() == 2);
+        EXPECT_EQUAL(*DSLWriter::ProgramElements()[0], "float sqr(float x);");
+        EXPECT_EQUAL(*DSLWriter::ProgramElements()[1], "void main() { sqr(5.0); }");
+        sqr.define(
+            Return(x * x)
+        );
+        REPORTER_ASSERT(r, DSLWriter::ProgramElements().size() == 3);
+        EXPECT_EQUAL(*DSLWriter::ProgramElements()[2], "float sqr(float x) { return (x * x); }");
+
+        const char* source = "source test";
+        std::unique_ptr<SkSL::Program> p = ReleaseProgram(std::make_unique<SkSL::String>(source));
+        EXPECT_EQUAL(*p,
+            "layout (builtin = 17) in bool sk_Clockwise;"
+            "float sqr(float x);"
+            "void main() {"
+            "/* inlined: sqr */;"
+            "25.0;"
+            "}");
+    }
+}