diff --git a/Changes b/Changes
index bb6993224..78fdb4a77 100644
--- a/Changes
+++ b/Changes
@@ -12,6 +12,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Fix false ALWCOMBORDER on interface references, bug1247. [Josh Redford]
 
+****  Fix constant propagation across DPI imports of inout strings. [Victor Besyakov]
+
 
 * Verilator 3.916 2017-11-25
 
diff --git a/src/V3Task.cpp b/src/V3Task.cpp
index 87a57f28d..00d7cacec 100644
--- a/src/V3Task.cpp
+++ b/src/V3Task.cpp
@@ -386,6 +386,9 @@ private:
 		    pinp->v3error("Function/task output connected to constant instead of variable: "+portp->prettyName());
 		}
 		else if (portp->isInout()) {
+		    // Correct lvalue; see comments below
+		    V3LinkLValue::linkLValueSet(pinp);
+
 		    if (AstVarRef* varrefp = pinp->castVarRef()) {
 			// Connect to this exact variable
 			AstVarScope* localVscp = varrefp->varScopep(); if (!localVscp) varrefp->v3fatalSrc("Null var scope");
@@ -489,6 +492,9 @@ private:
 		    pinp->v3error("Function/task output connected to constant instead of variable: "+portp->prettyName());
 		}
 		else if (portp->isInout()) {
+		    // Correct lvalue; see comments below
+		    V3LinkLValue::linkLValueSet(pinp);
+
 		    if (pinp->castVarRef()) {
 			// Connect to this exact variable
 		    } else {
diff --git a/test_regress/t/t_dpi_import.v b/test_regress/t/t_dpi_import.v
index 5f9cd0c1a..5e45da2bd 100644
--- a/test_regress/t/t_dpi_import.v
+++ b/test_regress/t/t_dpi_import.v
@@ -59,7 +59,7 @@ module t (/*AUTOARG*/
    import "DPI-C" pure function void dpii_v_struct   (input str_t     i, output str_t     o);
    import "DPI-C" pure function void dpii_v_substruct(input substr_t  i, output int       o);
    import "DPI-C" pure function void dpii_v_chandle  (input chandle   i, output chandle   o);
-   import "DPI-C" pure function void dpii_v_string   (input string    i, output string    o);
+   import "DPI-C" pure function void dpii_v_string   (input string    i, inout  string    o);
    import "DPI-C" pure function void dpii_v_real     (input real      i, output real      o);
 
    import "DPI-C" pure function void dpii_v_uint     (input int unsigned i,      output int unsigned o);