diff --git a/conf/airframes/airframe.dtd b/conf/airframes/airframe.dtd
new file mode 100644
index 0000000000..daca2fb8b6
--- /dev/null
+++ b/conf/airframes/airframe.dtd
@@ -0,0 +1,63 @@
+<!-- Paparazzi airframe DTD -->
+
+<!ELEMENT airframe (servos|commands|rc_commands|command_laws|section|makefile)*>
+<!ELEMENT servos (servo)*>
+<!ELEMENT commands (axis)*>
+<!ELEMENT rc_commands (set)*>
+<!ELEMENT command_laws (let|set)*>
+<!ELEMENT section (define|linear)*>
+<!ELEMENT servo EMPTY>
+<!ELEMENT axis EMPTY>
+<!ELEMENT set EMPTY>
+<!ELEMENT let EMPTY>
+<!ELEMENT define EMPTY>
+<!ELEMENT linear EMPTY>
+<!ELEMENT makefile (#PCDATA)>
+
+<!ATTLIST airframe
+name CDATA #IMPLIED>
+
+<!ATTLIST servos>
+
+<!ATTLIST commands>
+<!ATTLIST rc_commands>
+<!ATTLIST command_laws>
+
+<!ATTLIST section
+name CDATA #IMPLIED
+prefix CDATA #IMPLIED>
+
+<!ATTLIST servo
+name CDATA #REQUIRED
+no CDATA #REQUIRED
+min CDATA #REQUIRED
+neutral CDATA #REQUIRED
+max CDATA #REQUIRED>
+
+<!ATTLIST axis
+name CDATA #REQUIRED
+failsafe_value CDATA #REQUIRED>
+
+<!ATTLIST set
+value CDATA #REQUIRED
+command CDATA #IMPLIED
+servo CDATA #IMPLIED>
+
+<!ATTLIST let
+var CDATA #REQUIRED
+value CDATA #REQUIRED>
+
+<!ATTLIST define
+name CDATA #REQUIRED
+value CDATA #REQUIRED
+unit CDATA #IMPLIED>
+
+<!ATTLIST linear
+name CDATA #REQUIRED
+arity CDATA #REQUIRED
+coeff1 CDATA #REQUIRED
+coeff2 CDATA #IMPLIED
+coeff3 CDATA #IMPLIED>
+
+<!ATTLIST makefile
+target CDATA #IMPLIED>
diff --git a/conf/airframes/microjet5.xml b/conf/airframes/microjet5.xml
index 182138d69f..9ea001a81b 100644
--- a/conf/airframes/microjet5.xml
+++ b/conf/airframes/microjet5.xml
@@ -1,3 +1,5 @@
+<!DOCTYPE airframe SYSTEM "airframe.dtd">
+
 <airframe name="Microjet5">
  <!-- tiny test airframe -->
 
diff --git a/conf/airframes/plaster1.xml b/conf/airframes/plaster1.xml
index cf1a1f80ef..209696c828 100755
--- a/conf/airframes/plaster1.xml
+++ b/conf/airframes/plaster1.xml
@@ -1,5 +1,7 @@
 <!-- axi 2204-54 / GWS 8*4.3 / 3 lipos 740mah / 9.5a -->
 
+<!DOCTYPE airframe SYSTEM "airframe.dtd">
+
 <airframe name="Plaster White 1">
   <section name="adc" prefix="ADC_CHANNEL_">
     <define name="IR1" value="1"/>
@@ -8,7 +10,7 @@
     <define name="IR_NB_SAMPLES" value="16"/>
   </section>
 
-  <servos min="1000" neutral="1500" max="2000">
+  <servos>
     <servo name="GAZ"           no="0" min="1000" neutral="1000" max="1750"/>
     <servo name="AILEVON_RIGHT"  no="2" min="1800" neutral="1480" max="1200"/>
     <servo name="AILEVON_LEFT" no="6" min="1800" neutral="1440" max="1200"/>
@@ -51,8 +53,12 @@
     <define name="RAD_OF_IR_CONTRAST" value="0.6"/>
     <define name="RAD_OF_IR_MIN_VALUE" value="0.0008"/>
     <define name="RAD_OF_IR_MAX_VALUE" value="0.008"/>
+<!--
     <linear name="RollOfIrs" arity="2" coeff1="-1" coeff2="-1"/>
     <linear name="PitchOfIrs" arity="2" coeff1="-1" coeff2="1"/>
+-->
+    <define name="RollOfIrs(i1, i2)" value="(-i1 -i2)"/>
+    <define name="PitchOfIrs(i1, i2)" value="(i2-i1)"/>
     <define name="ADC_ROLL_NEUTRAL" value="-1042"/>
     <define name="ADC_PITCH_NEUTRAL" value="10"/>
   </section>
@@ -80,14 +86,14 @@
     <define name="ALTITUDE_PGAIN" value="-0.05"/>
     <define name="NAV_PITCH" value="0."/>
   </section>
-  <section name="BAT" channel="3">
+  <section name="BAT">
     <define name="MILLIAMP_PER_PERCENT" value="1.24"/>
     <define name="VOLTAGE_ADC_A" value="0.01727"/>
     <define name="VOLTAGE_ADC_B" value="0.2965"/>
     <define name="VoltageOfAdc(adc)" value="(VOLTAGE_ADC_A * adc + VOLTAGE_ADC_B)"/>
     <define name="LOW_BATTERY" value="9" unit="V"/>
   </section>
-  <section name="SERVOS" channel="6">
+  <section name="SERVOS">
     <define name="SERVOS_VOLTAGE_ADC_A" value="0.005661"/>
     <define name="SERVOS_VOLTAGE_ADC_B" value="0.014948"/>
     <define name="ServosVoltageOfAdc(adc)" value="(VOLTAGE_ADC_A * adc + VOLTAGE_ADC_B)"/>
diff --git a/conf/airframes/twinjet1.xml b/conf/airframes/twinjet1.xml
index 5b88f98a1e..cd1a409942 100644
--- a/conf/airframes/twinjet1.xml
+++ b/conf/airframes/twinjet1.xml
@@ -1,3 +1,5 @@
+<!DOCTYPE airframe SYSTEM "airframe.dtd">
+
 <airframe name="Twinjet">
 
   <servos>
diff --git a/sw/tools/gen_airframe.ml b/sw/tools/gen_airframe.ml
index 0d1200eafa..76ea7387d2 100644
--- a/sw/tools/gen_airframe.ml
+++ b/sw/tools/gen_airframe.ml
@@ -187,5 +187,8 @@ let _ =
     List.iter parse_section (Xml.children xml);
     finish h_name
   with
-    Xml.Error e -> prerr_endline (Xml.error e)
+    Xml.Error e -> prerr_endline (Xml.error e); exit 1
+  | Dtd.Parse_error e -> prerr_endline (Dtd.parse_error e); exit 1
+  | Dtd.Prove_error e -> prerr_endline (Dtd.prove_error e); exit 1
+  | Dtd.Check_error e -> prerr_endline (Dtd.check_error e); exit 1