diff --git a/Changes b/Changes
index f3f250292..526a53539 100644
--- a/Changes
+++ b/Changes
@@ -24,6 +24,7 @@ Verilator 4.211 devel
   C++ direct references to parameters might require updating (#3077). [Geza Lore]
 * Refactored Verilated include files; include verilated.h not verilated_heavy.h.
 * Add error when constant function under a generate (#3103). [Don Owen]
+* Add header guards on Dpi.h generated files (#2979). [Tood Strader]
 * Fix -G to treat simple integer literals as signed (#3060). [Anikin1610]
 * Fix emitted string array initializers (#2895). [Iztok Jeras]
 * Fix bitop tree optimization dropping necessary & operator (#3096). [Flavien Solt]
diff --git a/src/V3EmitCSyms.cpp b/src/V3EmitCSyms.cpp
index f86dd7487..fc430a369 100644
--- a/src/V3EmitCSyms.cpp
+++ b/src/V3EmitCSyms.cpp
@@ -940,6 +940,9 @@ void EmitCSyms::emitDpiHdr() {
     puts("// Verilator includes this file in all generated .cpp files that use DPI functions.\n");
     puts("// Manually include this file where DPI .c import functions are declared to ensure\n");
     puts("// the C functions match the expectations of the DPI imports.\n");
+
+    ofp()->putsGuard();
+
     puts("\n");
     puts("#include \"svdpi.h\"\n");
     puts("\n");
@@ -970,6 +973,8 @@ void EmitCSyms::emitDpiHdr() {
     puts("#ifdef __cplusplus\n");
     puts("}\n");
     puts("#endif\n");
+
+    ofp()->putsEndGuard();
 }
 
 //######################################################################
diff --git a/test_regress/t/t_dpi_arg_inout_type__Dpi.out b/test_regress/t/t_dpi_arg_inout_type__Dpi.out
index 01379ddcd..b800f7d8f 100644
--- a/test_regress/t/t_dpi_arg_inout_type__Dpi.out
+++ b/test_regress/t/t_dpi_arg_inout_type__Dpi.out
@@ -5,6 +5,9 @@
 // Manually include this file where DPI .c import functions are declared to ensure
 // the C functions match the expectations of the DPI imports.
 
+#ifndef VERILATED_VT_DPI_ARG_INOUT_TYPE__DPI_H_
+#define VERILATED_VT_DPI_ARG_INOUT_TYPE__DPI_H_  // guard
+
 #include "svdpi.h"
 
 #ifdef __cplusplus
@@ -152,3 +155,5 @@ extern "C" {
 #ifdef __cplusplus
 }
 #endif
+
+#endif  // guard
diff --git a/test_regress/t/t_dpi_arg_inout_unpack__Dpi.out b/test_regress/t/t_dpi_arg_inout_unpack__Dpi.out
index e4f0d5949..8c6d9be71 100644
--- a/test_regress/t/t_dpi_arg_inout_unpack__Dpi.out
+++ b/test_regress/t/t_dpi_arg_inout_unpack__Dpi.out
@@ -5,6 +5,9 @@
 // Manually include this file where DPI .c import functions are declared to ensure
 // the C functions match the expectations of the DPI imports.
 
+#ifndef VERILATED_VT_DPI_ARG_INOUT_UNPACK__DPI_H_
+#define VERILATED_VT_DPI_ARG_INOUT_UNPACK__DPI_H_  // guard
+
 #include "svdpi.h"
 
 #ifdef __cplusplus
@@ -181,3 +184,5 @@ extern "C" {
 #ifdef __cplusplus
 }
 #endif
+
+#endif  // guard
diff --git a/test_regress/t/t_dpi_arg_input_type__Dpi.out b/test_regress/t/t_dpi_arg_input_type__Dpi.out
index 632b44b9c..d0994c659 100644
--- a/test_regress/t/t_dpi_arg_input_type__Dpi.out
+++ b/test_regress/t/t_dpi_arg_input_type__Dpi.out
@@ -5,6 +5,9 @@
 // Manually include this file where DPI .c import functions are declared to ensure
 // the C functions match the expectations of the DPI imports.
 
+#ifndef VERILATED_VT_DPI_ARG_INPUT_TYPE__DPI_H_
+#define VERILATED_VT_DPI_ARG_INPUT_TYPE__DPI_H_  // guard
+
 #include "svdpi.h"
 
 #ifdef __cplusplus
@@ -152,3 +155,5 @@ extern "C" {
 #ifdef __cplusplus
 }
 #endif
+
+#endif  // guard
diff --git a/test_regress/t/t_dpi_arg_input_unpack__Dpi.out b/test_regress/t/t_dpi_arg_input_unpack__Dpi.out
index 0867d13f0..4d1afa518 100644
--- a/test_regress/t/t_dpi_arg_input_unpack__Dpi.out
+++ b/test_regress/t/t_dpi_arg_input_unpack__Dpi.out
@@ -5,6 +5,9 @@
 // Manually include this file where DPI .c import functions are declared to ensure
 // the C functions match the expectations of the DPI imports.
 
+#ifndef VERILATED_VT_DPI_ARG_INPUT_UNPACK__DPI_H_
+#define VERILATED_VT_DPI_ARG_INPUT_UNPACK__DPI_H_  // guard
+
 #include "svdpi.h"
 
 #ifdef __cplusplus
@@ -181,3 +184,5 @@ extern "C" {
 #ifdef __cplusplus
 }
 #endif
+
+#endif  // guard
diff --git a/test_regress/t/t_dpi_arg_output_type__Dpi.out b/test_regress/t/t_dpi_arg_output_type__Dpi.out
index 1a9db977f..e84de47c3 100644
--- a/test_regress/t/t_dpi_arg_output_type__Dpi.out
+++ b/test_regress/t/t_dpi_arg_output_type__Dpi.out
@@ -5,6 +5,9 @@
 // Manually include this file where DPI .c import functions are declared to ensure
 // the C functions match the expectations of the DPI imports.
 
+#ifndef VERILATED_VT_DPI_ARG_OUTPUT_TYPE__DPI_H_
+#define VERILATED_VT_DPI_ARG_OUTPUT_TYPE__DPI_H_  // guard
+
 #include "svdpi.h"
 
 #ifdef __cplusplus
@@ -152,3 +155,5 @@ extern "C" {
 #ifdef __cplusplus
 }
 #endif
+
+#endif  // guard
diff --git a/test_regress/t/t_dpi_arg_output_unpack__Dpi.out b/test_regress/t/t_dpi_arg_output_unpack__Dpi.out
index 24675921e..ddcd704de 100644
--- a/test_regress/t/t_dpi_arg_output_unpack__Dpi.out
+++ b/test_regress/t/t_dpi_arg_output_unpack__Dpi.out
@@ -5,6 +5,9 @@
 // Manually include this file where DPI .c import functions are declared to ensure
 // the C functions match the expectations of the DPI imports.
 
+#ifndef VERILATED_VT_DPI_ARG_OUTPUT_UNPACK__DPI_H_
+#define VERILATED_VT_DPI_ARG_OUTPUT_UNPACK__DPI_H_  // guard
+
 #include "svdpi.h"
 
 #ifdef __cplusplus
@@ -181,3 +184,5 @@ extern "C" {
 #ifdef __cplusplus
 }
 #endif
+
+#endif  // guard
diff --git a/test_regress/t/t_dpi_result_type__Dpi.out b/test_regress/t/t_dpi_result_type__Dpi.out
index cd2d0ecc8..344971158 100644
--- a/test_regress/t/t_dpi_result_type__Dpi.out
+++ b/test_regress/t/t_dpi_result_type__Dpi.out
@@ -5,6 +5,9 @@
 // Manually include this file where DPI .c import functions are declared to ensure
 // the C functions match the expectations of the DPI imports.
 
+#ifndef VERILATED_VT_DPI_RESULT_TYPE__DPI_H_
+#define VERILATED_VT_DPI_RESULT_TYPE__DPI_H_  // guard
+
 #include "svdpi.h"
 
 #ifdef __cplusplus
@@ -86,3 +89,5 @@ extern "C" {
 #ifdef __cplusplus
 }
 #endif
+
+#endif  // guard