diff --git a/ports/include/noux_session/sysio.h b/ports/include/noux_session/sysio.h
index 5729ebd73f..f3cf19b8b0 100644
--- a/ports/include/noux_session/sysio.h
+++ b/ports/include/noux_session/sysio.h
@@ -92,9 +92,10 @@ namespace Noux {
 		 */
 		struct Ioctl_in
 		{
-			enum Opcode { OP_UNDEFINED, OP_TIOCGWINSZ };
+			enum Opcode { OP_UNDEFINED, OP_TIOCGWINSZ, OP_FIONBIO };
 
 			Opcode request;
+			int argp;
 		};
 
 		/**
diff --git a/ports/src/lib/libc_noux/plugin.cc b/ports/src/lib/libc_noux/plugin.cc
index 01b9edfb5d..8caad5b2f2 100644
--- a/ports/src/lib/libc_noux/plugin.cc
+++ b/ports/src/lib/libc_noux/plugin.cc
@@ -861,9 +861,18 @@ namespace {
 
 			break;
 
+		case FIONBIO:
+			{
+				if (verbose)
+					PDBG("FIONBIO - *argp=%d", *argp);
+
+				sysio()->ioctl_in.request = Noux::Sysio::Ioctl_in::OP_FIONBIO;
+				sysio()->ioctl_in.argp = argp ? *(int*)argp : 0;
+			}
+
 		default:
 
-			PWRN("unsupported ioctl (request=0x%x", request);
+			PWRN("unsupported ioctl (request=0x%x)", request);
 			break;
 		}
 
@@ -892,6 +901,9 @@ namespace {
 				return 0;
 			}
 
+		case FIONBIO:
+			return 0;
+
 		default:
 			return -1;
 		}