diff --git a/changelog.md b/changelog.md
index bdd22d6ed..87d5a2a65 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,13 +1,9 @@
 ## Fixes/improvements
 
-* Reverted Internet Card code to OC 1.7.7, fixing the many related regressions.
-* Fixed "number expected, got number" being displayed instead of "number has no integer representation" on Lua 5.3+.
-* Fixed math.randomseed() not working with non-integer values.
+* [#3620] Fixed OC 1.8.0+ regression involving API arguments and numbers.
 
 ## OpenOS fixes/improvements
 
-* Fixed OpenOS version number.
-
 ## List of contributors
 
 asie
diff --git a/src/main/scala/li/cil/oc/server/machine/ArgumentsImpl.scala b/src/main/scala/li/cil/oc/server/machine/ArgumentsImpl.scala
index 27e5e30d2..c2edc71c9 100644
--- a/src/main/scala/li/cil/oc/server/machine/ArgumentsImpl.scala
+++ b/src/main/scala/li/cil/oc/server/machine/ArgumentsImpl.scala
@@ -58,10 +58,28 @@ class ArgumentsImpl(val args: Seq[AnyRef]) extends Arguments {
   }
 
   def checkInteger(index: Int) = {
-    checkIndex(index, "number")
+    checkIndex(index, "integer")
     args(index) match {
+      case value: java.lang.Double =>
+        if (!java.lang.Double.isFinite(value) || value < java.lang.Integer.MIN_VALUE || value > java.lang.Integer.MAX_VALUE) {
+          throw intError(index, value)
+        } else {
+          value.intValue
+        }
+      case value: java.lang.Float =>
+        if (!java.lang.Float.isFinite(value) || value < java.lang.Integer.MIN_VALUE || value > java.lang.Integer.MAX_VALUE) {
+          throw intError(index, value)
+        } else {
+          value.intValue
+        }
+      case value: java.lang.Long =>
+        if (value < java.lang.Integer.MIN_VALUE || value > java.lang.Integer.MAX_VALUE) {
+          throw intError(index, value)
+        } else {
+          value.intValue
+        }
       case value: java.lang.Number => value.intValue
-      case value => throw typeError(index, value, "number")
+      case value => throw typeError(index, value, "integer")
     }
   }
 
@@ -71,10 +89,22 @@ class ArgumentsImpl(val args: Seq[AnyRef]) extends Arguments {
   }
 
   def checkLong(index: Int) = {
-    checkIndex(index, "number")
+    checkIndex(index, "integer")
     args(index) match {
+      case value: java.lang.Double =>
+        if (!java.lang.Double.isFinite(value) || value < java.lang.Long.MIN_VALUE || value > java.lang.Long.MAX_VALUE) {
+          throw intError(index, value)
+        } else {
+          value.longValue
+        }
+      case value: java.lang.Float =>
+        if (!java.lang.Float.isFinite(value) || value < java.lang.Long.MIN_VALUE || value > java.lang.Long.MAX_VALUE) {
+          throw intError(index, value)
+        } else {
+          value.longValue
+        }
       case value: java.lang.Number => value.longValue
-      case value => throw typeError(index, value, "number")
+      case value => throw typeError(index, value, "integer")
     }
   }
 
@@ -157,22 +187,31 @@ class ArgumentsImpl(val args: Seq[AnyRef]) extends Arguments {
 
   def isDouble(index: Int) =
     index >= 0 && index < count && (args(index) match {
-      case value: java.lang.Float => true
-      case value: java.lang.Double => true
+      case value: java.lang.Number => true
       case _ => false
     })
 
   def isInteger(index: Int) =
     index >= 0 && index < count && (args(index) match {
-      case value: java.lang.Byte => true
-      case value: java.lang.Short => true
-      case value: java.lang.Integer => true
-      case value: java.lang.Long => true
-      case value: java.lang.Double => true
+      case value: java.lang.Double =>
+        java.lang.Double.isFinite(value) && value >= java.lang.Integer.MIN_VALUE && value <= java.lang.Integer.MAX_VALUE
+      case value: java.lang.Float =>
+        java.lang.Float.isFinite(value) && value >= java.lang.Integer.MIN_VALUE && value <= java.lang.Integer.MAX_VALUE
+      case value: java.lang.Long =>
+        value >= java.lang.Integer.MIN_VALUE && value <= java.lang.Integer.MAX_VALUE
+      case value: java.lang.Number => true
       case _ => false
     })
 
-  def isLong(index: Int) = isInteger(index)
+  def isLong(index: Int) =
+    index >= 0 && index < count && (args(index) match {
+      case value: java.lang.Double =>
+        java.lang.Double.isFinite(value) && value >= java.lang.Long.MIN_VALUE && value <= java.lang.Long.MAX_VALUE
+      case value: java.lang.Float =>
+        java.lang.Float.isFinite(value) && value >= java.lang.Long.MIN_VALUE && value <= java.lang.Long.MAX_VALUE
+      case value: java.lang.Number => true
+      case _ => false
+    })
 
   def isString(index: Int) =
     index >= 0 && index < count && (args(index) match {
@@ -222,6 +261,10 @@ class ArgumentsImpl(val args: Seq[AnyRef]) extends Arguments {
     new IllegalArgumentException(
       s"bad argument #${index + 1} ($want expected, got ${typeName(have)})")
 
+  private def intError(index: Int, have: AnyRef) =
+    new IllegalArgumentException(
+      s"bad argument #${index + 1} (${typeName(have)} has no integer representation)")
+
   private def typeName(value: AnyRef): String = value match {
     case null | Unit | None => "nil"
     case _: java.lang.Boolean => "boolean"
@@ -229,7 +272,7 @@ class ArgumentsImpl(val args: Seq[AnyRef]) extends Arguments {
     case _: java.lang.Short => "integer"
     case _: java.lang.Integer => "integer"
     case _: java.lang.Long => "integer"
-    case _: java.lang.Number => "double"
+    case _: java.lang.Number => "number"
     case _: java.lang.String => "string"
     case _: Array[Byte] => "string"
     case value: java.util.Map[_, _] => "table"