diff --git a/app/src/main/kotlin/org/fossify/contacts/helpers/VcfExporter.kt b/app/src/main/kotlin/org/fossify/contacts/helpers/VcfExporter.kt
index bfea1cccd..979132984 100644
--- a/app/src/main/kotlin/org/fossify/contacts/helpers/VcfExporter.kt
+++ b/app/src/main/kotlin/org/fossify/contacts/helpers/VcfExporter.kt
@@ -156,7 +156,22 @@ class VcfExporter {
                         Im.PROTOCOL_GOOGLE_TALK -> Impp(HANGOUTS, it.value)
                         Im.PROTOCOL_QQ -> Impp(QQ, it.value)
                         Im.PROTOCOL_JABBER -> Impp(JABBER, it.value)
-                        else -> Impp(it.label, it.value)
+                        else -> {
+                            // IMPP URIs use the label as the URI scheme, which only allows
+                            // [a-zA-Z][a-zA-Z0-9+-.]*. Replace any character outside that
+                            // set with a hyphen so labels containing spaces (or other symbols)
+                            // don't throw an IllegalArgumentException and corrupt the export.
+                            val scheme = it.label
+                                .replace(Regex("[^a-zA-Z0-9+\\-.]"), "-")
+                                .let { s ->
+                                    when {
+                                        s.isEmpty() -> "x-custom"
+                                        s.firstOrNull()?.isLetter() != true -> "x-$s"
+                                        else -> s
+                                    }
+                                }
+                            Impp(scheme, it.value)
+                        }
                     }
 
                     card.addImpp(impp)